230 INTERNAL SECRETIONS 



examined 376 radiated women, concludes that in young 

 individuals the activity of the ovary is stopped only temporarily, 

 that a complete return to a normal state is possible; this is 

 shown by the fact that, after amenorrhoea, caused by irradia- 

 tion, menstruation almost always reappears after a certain 

 time ; women treated by irradiation can conceive subsequently, 

 and give birth to entirely normal children. 



In view of these considerations, it is easy to understand that 

 the reaction of the ovary to irradiation is an extraordinarily 

 manifold one. 



The influence of the strength of irradiation on the mode of 

 reaction of the ovary has been investigated by different 

 authors, and most recently by Steinach and Holzknecht 

 (1916). They stated that by an unique irradiation of a certain 

 strength (about 12 "Holzknecht-units") an obhteration of 

 the follicles and an increase of interstitial cells can be obtained 

 in guinea pigs {Figs. 105 B and 106 B). By an unique 

 irradiation of a greater strength both folhcles and interstitial 

 tissue can be destroyed. Even by merely changing the position 

 of the animal, for instance, by irradiating the ventral instead of 

 the dorsal side, the same strength will cause destruction of 

 interstitial tissue instead of hypertrophy. We see that only 

 those experiments can be compared with one another where 

 exact doses of X-rays have been given, and where all the other 

 conditions of the experiment have been the same. As long as 

 quantitative relations are not duly considered, there can be no 

 possibihty of any agreement between different authors con- 

 cerning the influence of X-rays on the ovary; the position is the 

 same here as with any other stimulus known to the 

 physiologist. 



Bouin, Ancel and Villemin (1906-1907), working on the 

 rabbit, were the first to show that an obhteration of the 

 follicles can be caused by X-rays, the interstitial cells remaining 

 intact. Houssy and Wallart (1915) showed that an increase 

 of the interstitial tissue may take place in the ovary of man 

 when irradiated on account of uterine myoma. Similar 

 observations were made by Hewer (1915, P- 444) on white rats, 

 and by Aschner (1918, p. 45) on the dog. In view of these 

 observations there can be no doubt that by the employment of 

 regulated doses an atresia of a very large number of folhcles 

 and a great increase of interstitial cells can be obtained. 



